Guide rails are used to guide the vertical movement of an elevator car in an elevator shaft. Usually there are two guide rails on the opposite walls of the elevator shaft and the elevator car is located between them and linked to the guide rails through guide shoes or guide rollers facing the guide rails. Guide rails are constructed from multiple guide rail sections that are connected to each other from their vertical ends to form a continuous guiding structure for the elevator. The connection between two adjacent guide rail sections is secured through a connecting element, for example a fishplate, that is attached to both guide rail sections through bolts or similar. The guide rails are attached to the walls of the elevator shaft through brackets.
If the elevator is equipped with a counterweight, it typically runs along its own guide rails. The counterweight guide rails have a similar structure as the elevator car guide rails, but they are usually located closer to each other and they can be attached to the same wall.
Guide rails are typically installed in the elevator shaft in a bottom-up manner. The vertical line in which each guide rail should run is first established with the aid of a plumb line or a laser beam. The two bottom-most guide rail sections of a given guide rail pair are then attached to the walls through the brackets. The straightness of the guide rail sections is checked and adjusted through the brackets if necessary. Then, the next pair of guide rail sections is mounted on top of the first pair and attached to the wall as the previous guide rail sections. The straightness of the guide rail sections is checked in relation to the guide rail section below and adjusted through the brackets if necessary. The fishplate is then added at the formed junction and the ends are aligned. The process is repeated until all guide rails are complete.
Guide rail sections are usually several meters (feet) in length and made of steel. They are thus heavy and their handling during installation requires caution. During the installation of the guide rails, a temporary scaffold or a lift can be constructed in the elevator shaft for transporting material. The system usually incorporates a working platform, from which the installation work is performed. Usually, one guide rail section is attached to the working platform at the bottom floor of the elevator shaft or at an intermediate level where the guide rails are pre-transported. The guide rail section is then driven with the working platform to the installation height, installed and the next guide rail section is retrieved. Transporting the guide rail sections one by one is time-consuming and is a significant bottleneck during the elevator installation.
In the document WO 2009/092844 A1, a method for installing an elevator and guide rails of an elevator are disclosed. In the method, first the lowermost pair of guide rail sections is installed and at least one working platform is built between the guide rails. After this, the guide rail sections of the second pair of guide rail sections are fixed as an extension of the guide rails using the built working platform as an aid. Then, diverting pulleys are fixed to the top ends of the second guide rail sections and a hoist is fitted to the working platform for lifting the working platform upwards. Then, the rope suspension of the working platform is fitted so that the hoisting rope is arranged to pass at its first end from the hoist over the diverting pulleys at the top end of the guide rails and under the diverting pulleys that are in connection with the working platform to its fixing point of the second end of the working platform. After this, the working platform is lifted to the next working height by means of the hoist and is locked into position.
The drawbacks of the current solutions are that each guide rail is individually transported to the working height, which is very slow. Further, installation works have to be stopped for the time during which the next guide rail section is retrieved. The problems are exacerbated in high-rise buildings where the elevator hoisting distance is high and the time needed for the transportation of the guide rail section increases accordingly.